The human spine with its many vertebrae separated from each other by resilient discs and having nerves branching out from openings between adjacent vertebrae is the source of many of mankinds aches and pains. In order to prevent many back pains it is important to maintain the spine in its natural curvature during periods of rest, principally while sleeping. The conventional flat top mattress supports only the convex parts of the body that protrude outwardly, such as the heels, buttocks, thoracic spine, shoulders, and head. The concave portions of the body such as the neck, small of the back, back of the knees, etc. are not supported unless the mattress is extremely soft and this can also cause problems. Such unsupported portions of the body are found regardless of whether the sleeper lies on his back (supine), on his stomach (prone), or on his side.
Many prior art workers have tried to design a mattress that will support more of the body than those portions resting on a flat top mattress. None of these provides full support for all sleeping positions.
In U.S. Pat. No. 2,373,421 to Schenker there is disclosed an innerspring mattress which has contours that are overly accentuated in the thoracic and lumbar areas and does nothing for the knee area. More specifically, Schenker provides excessive lumbar support when the person is in the side posture; the alleged hamstring relaxer is not sufficiently elevated to effect a proper bend in the knee, i.e., one which effectively relaxes the muscles beneath the knee; it appears to provide a hyperlordotic lumbar curvature; it produces an excessive anterior pelvic tilt; it causes the thoracic spine to bend in a hyperkyphotic manner; and it causes kyphotic lumbar curvature in the prone position, which often results in intervertebral disc protrusion.
In U.S. Pat. No. 2,861,278 to Young there is disclosed an innerspring mattress which provides only a single convex portion in the lumbar area and ignores all other portions of the body. Young appears to be deficient in many areas in having no hamstring relaxing effect; no superior hip relaxation in the side posture; and only one elevated surface on the device usable beneath the mattress.
In U.S. Pat. No. 3,885,258 to Regan there is a disclosure of a foam rubber mattress of several layers which results in improper support in the lumbar and knee areas. Lack of lumbar support in Regan may, in the prone posture, cause hyperlordosis of lumbar vertebrae (sway back), an unnatural lumbar sacral tilt, and hyperextended lumbar spine. In the supine position flattening of the spine occurs due to the fact that support of the buttocks and the mid-thoracic regions leaves the lumbar region in a hypolordotic unnatural position. In the supine position increased popliteal fossa strain is produced due to support of the calf. In the side position lateral curvature of the spine is likely to occur.
In U.S. Pat. No. 4,207,635 to Leroy there is a disclosure of a sun tanning lounge which purports to support the body in prone and supine positions but which does not provide the proper support in the lumbar and knee areas. Leroy's furniture produces a hypolordosis of the lumbar spine in the supine position; there is no hamstring relaxer; and an increase in kyphotic lumbar curvature is intentionally produced; which is the curvature causing lumbar spine problems. Leroy's support has only a single elevated surface which provides support in the prone position and must be turned over for the supine position, and no provision for use as a side support.
It is an object of this invention to provide an improved contoured support to properly maintain the spine in its natural comfortable curvature. It is another object of this invention to provide such support when the body is in the prone, supine, or side position. A further object is to provide a contoured support for the entire body to reduce and/or inhibit intervertebral disc protrusion and provide therapeutic easing of pain by those suffering from such protrusions, particularly in the lordotic lumbar area. Still other objects will appear from the more detailed description which follows: